Wow. Your friend did not deserve to be bullied like that. Everyone has their preferences, but I haven't seen the KittyCats fans behaving like this, thankfully.
I think this had more to do with those people wanting to be jerks online than a difference of opinion on a style of cat. There really is no excuse for behavior like that and that place has probably lost her business.
I have a few of the
other kitties because they are quite different so each type really offers a different game. KittyCats were my first though, so the other breedables all owe KittyCats for getting me addicted.
I hope your friend found a much friendlier place to sell her cats.